Metabolite profiling of sheath blight disease resistance in rice: in the case of positive ion mode analysis by CE/TOF-MS

Rice sheath blight is an important disease caused by Rhizoctonia solani. The resistant and susceptible rice lines (32R and 29S, respectively) showed different responses to R. solani infection in metabolite levels. The aim of this study was to characterize the metabolite levels in rice lines during R. solani infection using capillary electrophoresis equipped with time of flight mass spectrophotometry (CE/TOF-MS) in positive ion mode. Hundred metabolites were identified and classified into six clusters by hierarchical cluster using Mass Profiler Professional software. Changes in metabolite level at inoculated 32R and 29S were mapped on branches of tricarboxylic acid and glycolysis pathway. Volcano plot successfully filtered the metabolites based on fold change and p-value. The volcano plot result showed that 10 metabolites were up and down regulated in inoculated 32R relative to 29S. One metabolite, chlorogenic acid, showed a positive response in 32R. Meanwhile, pipecolic acid showed as the highest magnitude of fold change and p-value significance level in 29S. In addition, eight amino acids; glutamate, γ-aminobutyric acid, glycine, histidine, phenylalanine, serine, tryptophan, and tyrosine showed increase in 29S after R. solani inoculation.     

飞行时间质谱在烟草化学中的应用概述

简要综述了飞行时间质谱技术的特点及其在烟草、卷烟烟丝、主流烟气和烟用辅料分析上的应用,并展望了其在烟草化学领域的发展前景。     

不同采收期刺五加叶黄酮类成分动态变化分析

目的 研究刺五加叶不同采收时期黄酮类化合物含量变化规律。方法 分别采用紫外分光光度法以及UPLC-Q/TOF-MS技术对不同采收时期的刺五加叶进行总黄酮的含量测定以及黄酮类化合物的成分分析，并分别进行刺五加叶不同采收时期的黄酮类化合物趋势研究。 结果 刺五加叶总黄酮含量分别在5月初、8月中旬、9月末较高，在5月到8月这段生长季节含量有所下降，共找出11个明显上升趋势，11个明显下降趋势的黄酮类化合物并予以趋势分析，结果表明两种方法得到的不同采收时期刺五加叶总黄酮含量变化趋势一致。结论 刺五加叶不同采收时期黄酮类化合物含量变化具有明显趋势，本实验为更好的开发和利用刺五加叶提供了理论依据。     

基于飞行时间质谱原位检测的5种绿化植物异戊二烯释放速率

异戊二烯是一种重要的植物挥发性有机物(biogenic volatile organic compounds,BVOCs),约占全球BVOCs释放总量的44%,被认为是臭氧和二次气溶胶的重要来源。封闭式采样-热脱附-气质联用(GC-MS)是目前广泛使用的异戊二烯检测方法,但存在分析周期长、步骤复杂、时间分辨率低、易产生系统误差等问题,影响测试结果的准确性和时效性。本研究通过封闭式采样法收集样品,并引入飞行时间质谱仪(TOF-MS)进行原位分析,建立了一种植物源异戊二烯的原位检测方法,并利用该方法测量了5种园林绿化植物异戊二烯的排放速率。结果表明,垂柳的异戊二烯排放速率最高,在夏季可达到14.94μg/g/h,而香樟、女贞、珊瑚树排放速率都较低;植物释放异戊二烯的速率在不同季度间也存在差异,夏季释放速率高于其他季节,冬季释放速率最低。根据该方法与传统方法比较,2种测试结果没有显著差异。新方法可用于植物BVOCs排放的快速准确检测。     

Protective effect of high-oleic acid peanut oil and extra-virgin olive oil in rats with diet-induced metabolic syndrome by regulating branched-chain amino acids metabolism

High-oleic acid peanut oil (HOPO) and extra-virgin olive oil (EVOO) have been reported previously to have an attenuating effect on metabolic syndrome (MS). This study aimed to evaluate the metabolic effect of HOPO and EVOO supplementation in attenuating MS and the role of gut microbiota in regulating the metabolic profile. Sprague-Dawley rats were continuously fed with a normal diet, high-fructose and high-fat (HFHF) diet, HFHF diet containing HOPO, or a HFHF diet containing EVOO for 12 weeks. The metabolomics profiles of feces and serum samples were compared using untargeted metabolomics based on UPLC-Q/TOF-MS. Partial Least Squares Discriminant Analysis (PLS-DA) was used to identify the potential fecal and serum biomarkers from different groups. Correlation between gut microbiota and biomarkers was assessed, and pathway analysis of serum biomarkers was conducted. Differences in metabolic patterns in feces and serum were observed among different groups. There were 8 and 12 potential biomarkers in feces and 15 and 6 potential biomarkers in serum of HOPO group and EVOO group, respectively, suggesting that HOPO and EVOO supplementation mainly altered amino acids, peptides, and their analogs in feces and serum. The branched-chain amino acids (BCAAs) biosynthesis pathway was identified as a major pathway regulated by HOPO or EVOO. This study suggests that HOPO and EVOO supplementation ameliorate diet-induced MS, mainly via modulation of the BCAAs biosynthesis pathway.     

‘春甜橘’及其突变体果皮差异相关蛋白质组分析

【目的】柑橘自然芽变材料是柑橘育种的重要来源。‘明柳甜橘’(Citrus reticuiata Blancocv.Mingliutianju,MP)是从‘春甜橘’(C.reticuiata Blanco cv.Chuntianju,CP)中选育出的自然芽变品种。分析‘春甜橘’与其自然芽变‘明柳甜橘’果皮差异蛋白质,探讨导致两品种形态差异的原因。【方法】以花后12周和23周的‘明柳甜橘’和‘春甜橘’果皮为材料,采用双向电泳技术(Two-dimensional gel electrophoresis,2-DE)分离获得野生型与突变型差异表达蛋白点,利用MALDI-TOF-MS质谱鉴定技术分析相关差异蛋白质,并进行功能注释和生物信息学分析。【结果】将提取的果皮总蛋白质经双向电泳后,分别采用硝酸银和考马斯亮蓝染色法进行蛋白质凝胶染色,均获得了清晰的2-DE电泳图。2-DE图谱经Image Master 2D软件分析表明,硝酸银染色法能检测到约1 200个蛋白点,考马斯亮蓝染色法能检测到约500个蛋白质点,从中各选取20个变化丰度2倍以上且重复性好的蛋白点进行MALDI-TOF-MS质谱鉴定和数据库检索分析,共有33个蛋白质有功能注释,其中17个蛋白质在‘明柳甜橘’果皮中表达上调,16个表达下调。按照33个差异蛋白质的功能,可将其分为11类,它们分别参与糖类/能量代谢、胁迫/防御反应、核酸代谢、氨基酸代谢、转录、氮代谢、脂肪酸代谢、蛋白修饰与降解以及未知类。利用KOBAS(KEGG Orthology-Based Annotation System)在线功能分析平台对33个差异表达蛋白质进行信号通路分析,其中18个差异蛋白质有KO注释,共涉及31条信号通路,按照P值大小排列,类黄酮生物合成过程位居第一,说明该信号通路最有可能参与春甜橘芽变形成过程。【结论】综合分析‘春甜橘’和‘明柳甜橘’基因水平及蛋白质水平的差异,推测可能是由参与类黄酮生物合成过程的差异表达基因尿苷二磷酸葡萄糖基转移酶基因和差异表达蛋白咖啡酰辅酶A-O-甲基转移酶的差异表达导致了二者的表型差异。     

质谱法在食品样本农药残留分析中的应用进展

质谱法(Mass spectrometry,MS)是当前农药残留分析中的主导检测技术。对气相色谱-质谱法(GC-MS)、气相色谱-串联质谱法(GC-MS/MS)、液相色谱-串联质谱法(LC-MS/MS)和飞行时间质谱法(time-of-flight mass spectrometry,TOF-MS)在食品样本农药残留分析中的应用进行了综述,重点对质谱技术在国内外多残留分析方法研究中的应用进展进行了总结和归纳,简要比较了质谱分析时常用的几种样品前处理技术的优缺点及其适用性,展望了质谱法在农药残留分析研究领域的发展前景。     

椰浆中椰子蛋白的提取、分离和鉴定

为了更好地了解市售椰浆中椰子蛋白质量状况,本研究以市售的10种椰浆为样品,采用反向高效液相色谱（reversed-phase high performance liquid chromatography,RP-HPLC）及十二烷基磺酸钠-聚丙烯酰胺凝胶电泳（sodium laurylsulfonate-polyacrylamide gel electrophoresis,SDS-PAGE）对提取蛋白进行分析,采用基质辅助激光解吸电离飞行时间串联质谱（matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry,MALDI-TOF/TOF-MS）对蛋白进行鉴定。结果表明：椰浆RP-HPLC约在10.4 min和11.9 min分别出现1个色谱峰,大多数样品峰面积大小都与蛋白标签含量一致,SDS-PAGE条带数量和颜色的深浅与RP-HPLC得到的峰面积结果一致,个别样品标签含量高,SDS-PAGE能分离出的蛋白条带数量也较多,但RP-HPLC的椰子蛋白峰面积小,经MALDI-TOF/TOF-MS鉴定,部分条带没有鉴定出椰子有关的肽段或蛋白。研究结果为椰浆蛋白的食品安全与质量控制提供了方法参考和示范。